This invention relates to the electrical circuit for the operation of automobile horns, and more particularly to a particular type of metallic brush utilized in certain imported and domestic vehicles to provide an electrical connection between the operating coil of the horn or horn relay which is normally somewhere under the hood of the vehicle, and the horn button or switch which is on the steering wheel. Normally the horn or horn relay coil has one of its terminals permanently connected to the plus or non-grounded terminal of the vehicle's battery and the other terminal is connected to a horn wire which runs up the steering column to the horn switch or button. When operated, the horn switch grounds this wire usually through the metallic steering shaft and wheel to complete the circuit to the horn. An electrical brush and slip ring is required to complete the electrical circuit to the rotary steering wheel. The auto horn circuit to which the present invention is applicable comprises a slip ring on the underside of the steering wheel which engages the upper end of an elongated metal rod which is mounted in an insulated control yoke which surrounds the steering shaft just under the steering wheel and which supports other control devices such as the vehicle's directional signals, windshield wiper and washers, etc. The elongated rod is mounted in a hole in an insulated portion of the control yoke and is spring loaded so that the enlarged upper portion thereof forms an electrical brush which rides on the slip ring. The horn wire is attached to the other or lower end of the metal rod.
In normal use the constant turning of the steering wheel causes the electrical brush to wear down and eventually the head wear is such that electrical contact can no longer be made and the horn becomes inoperative. Prior to the present invention, in order to repair this defect it was necessary to replace the entire metal rod. This was a time consuming and hence costly job which required removal of the steering wheel and the aforementioned control yoke, since it was necessary to disconnect the horn wire from the lower or tail end of the rod which is on the underside of the control yoke, before the old rod could be removed.